A cutting insert (indexable insert) described in Patent Document 1 has been known as a tool used in the milling process. The cutting insert described in Patent Document 1 includes a chamfered part between a major cutting edge and a minor cutting edge. A chamfer that is a kind of honing is provided along the chamfered part. The chamfer on the chamfered part has a straight line shape. The minor cutting edge functions as a so-called wiper cutting edge.
The chamfer in the cutting insert described in Patent Document 1 has the straight line shape and is away from the major cutting edge. Therefore, the chamfered part has high strength, whereas the major cutting edge may have insufficient strength.